The overall objective of the project is to delineate the control mechanism of gluconeogenesis in the neonatal pig liver under a variety of substrate and hormonal influences. The goals for the coming year are: 1) to determine the ability of the isolated neonatal pig liver to autoregulate glucose levels, 2) demonstrate glucagon stimulation of gluconeogenesis in the perfused liver, 3) determine in isolated pig liver mitochondria, efflux rates of malate, citrate, PEP when pyruvate is the substrate, and 4) to determine the role of mitochondrial carriers in PEP formation during hormonal stimulation (glucagon) of gluconeogenesis.